The Pan American Health Organization (PAHO) is warning countries across the Americas to tighten vaccination and disease surveillance measures as the risk of measles spreading across the Region remains “very high,” with confirmed cases almost five times higher than last year.
The warning comes ahead of several major religious gatherings expected in South America in the coming months, which could lead to increased travel within and between countries and create further opportunities for the highly contagious virus to spread.
According to PAHO, 55,792 confirmed measles cases and 77 deaths were recorded across 17 countries and territories between January 4 and October 3, 2026.
That represents a 4.8-fold increase in cases compared with the corresponding period last year.
While Guyana was not listed among the countries reporting confirmed cases, PAHO said the movement of people across borders and ongoing outbreaks elsewhere in the Region mean countries must remain prepared for imported cases.
“Measles is highly contagious, and we are seeing the consequences of gaps in vaccination coverage across the Americas,” PAHO Director Dr. Jarbas Barbosa said.
He urged parents to ensure their children are protected with the measles, mumps and rubella (MMR) vaccine, while calling on governments to close vaccination gaps and strengthen their ability to rapidly detect and respond to cases.
Guatemala has recorded the largest number of measles cases in the Region, followed by Mexico, the United States, Peru and Canada. Together, the five countries account for 99.5% of confirmed cases.
Cases have also been detected in Argentina, Belize, Bolivia, Bonaire, Brazil, Chile, Colombia, Costa Rica, El Salvador, Honduras, Panama and Uruguay.
PAHO said the threat is being compounded by rising measles cases globally, increasing the possibility of infected travellers carrying the virus into countries and communities where vaccination levels are low.
The organisation noted that people infected with measles can transmit the virus even before the characteristic rash develops, allowing travellers to unknowingly expose others.
PAHO Executive Manager of Comprehensive Immunization, Dr. Daniel Salas, advised persons planning to attend large gatherings to check their vaccination status.
“Anyone planning to attend a large gathering should check that they are protected against measles,” Salas said.
He said persons six months and older without evidence of vaccination should receive a dose of measles-rubella vaccine before travelling or attending a mass gathering, preferably at least two weeks beforehand.
Vaccination coverage across the Americas remains below the level PAHO says is necessary to prevent outbreaks.
In 2025, regional coverage stood at 88% for the first MMR dose and 85% for the second, below the 95% target. An estimated 1.6 million children across the Americas received no measles vaccine at all last year.
PAHO said the gaps are linked to several factors, including setbacks during the COVID-19 pandemic, vaccine hesitancy, difficulties delivering vaccines and barriers to healthcare among some Indigenous, migrant and displaced populations.
The health body is now urging countries to use every opportunity to vaccinate unprotected persons while maintaining strong surveillance and rapid-response systems.
Measles can cause serious complications at any age, but PAHO said infants, children under five, adults and persons affected by malnutrition or with limited access to healthcare face greater risks of severe illness and death.
